1. Field of the Invention
This invention relates to vises and particularly vises for use in holding articles during machining operations so as to achieve a high degree of accuracy of machine work.
Vises in this field, although usually small, are quite heavy in order to effectively fix the position of a piece to be worked upon. The vises normally have a base, a jaw fixed to the base, and a movable jaw which slides into position. In the past, vises of this type have used various means for clamping an article to be machined within the vise. To date, these means have been ineffective to assure tolerances of 0.0002 inches. The vises customarily have a groove around the side or over the top, or both, for clamping the entire vise, with article to be machined therein, onto a drill or similar machine. Generally, the problem of tolerances does not involve holding the vise on the machine.
2. Description of the Prior Art
Many devices have been invented in the past to provide accurate machine tolerances.
Beusch, in U.S. Pat. No. 2,803,999, describes a device with handles which tighten a movable jaw into position against a stationary jaw. Similarly, Paret, in U.S. Pat. No. 3,630,512, describes a device which uses a screw that turns by a key in the screw head to make a fine adjustment in the vise. Graether, in U.S. Pat. No. 2,511,843 shows a vise with both a stationary and a movable jaw. Graether uses a screw shaft with a hand wheel thereon for tightening the jaws together. Also known is Renner, U.S. Pat. No. 2,552,738. Renner uses a nut on a threaded shank in order to tighten the jaws of the small vise together. Renner uses a threaded member and a threaded bore within the base of the vise for cooperation to achieve a locking/holding effect for a shank, whereby the jaws are moved together upon tightening of the nut on the shank.
To date, none of these devices or similar devices have been able to consistently achieve the tolerences required, such as 0.0002 inches.